Hey
So I’m sure you know how to do it but are probably confused as to how to grab the arguments outside the array.
So in the function: arr is simply arguments[0] that is [1, 2, 3, 1, 2, 3].

The best practice is to grab arguments and put them in an array of their own
eg to grab all arguments do var x = Array.prototype.slice.call(arguments);
to grab from arguments[n] first
var x = Array.prototype.slice.call(arguments, 1) //this code pushes every arguments[1], arguments[2], arguments[3] etc into x